Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.

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Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable.

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Indicates (true/false) whether practical expedient is elected under initial application of retrospective method not to restate completed contracts that begin and end in same annual reporting period.

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Revenue Recognition, Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018
Revenue, Practical Expedient [Abstract]
Revenue recognition completed contract, practical expedient		false
Revenue recognition [Line Items]
Cumulative effect of accounting changes	$ 193	$ 193
Bad debts expense		$ 43	$ 49
Capitalized contract cost
Capitalized contract cost, amortization method		Capitalized commission fees and fulfillment costs are amortized based on the transfer of the goods or services to which the assets relate, typically the contract term which ranges from thirteen months to five years.
Amortization of contract cost assets	30	$ 62
Impairment of capitalized contract cost	0	0
Retained earnings
Revenue recognition [Line Items]
Cumulative effect of accounting changes	163	163
Revenue from contract with customer
Revenue recognition [Line Items]
Bad debts expense	$ 23	$ 43
ASU 2014-09 \| Retained earnings
Revenue recognition [Line Items]
Cumulative effect of accounting changes				$ 163
ASU 2017-05 \| Retained earnings
Revenue recognition [Line Items]
Cumulative effect of accounting changes				$ 0